U.S. patent number 9,376,786 [Application Number 14/239,054] was granted by the patent office on 2016-06-28 for construction machine.
This patent grant is currently assigned to KOBELCO CONSTRUCTION MACHINERY CO., LTD.. The grantee listed for this patent is Masaru Numasawa. Invention is credited to Masaru Numasawa.
United States Patent |
9,376,786 |
Numasawa |
June 28, 2016 |
Construction machine
Abstract
In a construction machine having an engine room and capable of
efficiently collecting air flowing in the engine room, a heat
exchanger provided at a first side of the engine, and a fan
provided at the first side and rotating to generate around the
engine a flow of cooling air, further includes an exhaust duct
extending in a fan axial direction parallel with a rotation axis of
the fan along the engine. The exhaust duct guides the flow of the
air to collect the air flowing downstream of the fan in the fan
axial direction, in a region extending in the fan axial direction,
and discharges the air to an outside of the engine room.
Inventors: |
Numasawa; Masaru (Hiroshima,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Numasawa; Masaru |
Hiroshima |
N/A |
JP |
|
|
Assignee: |
KOBELCO CONSTRUCTION MACHINERY CO.,
LTD. (Hiroshima-shi, JP)
|
Family
ID: |
47746123 |
Appl.
No.: |
14/239,054 |
Filed: |
August 7, 2012 |
PCT
Filed: |
August 07, 2012 |
PCT No.: |
PCT/JP2012/005013 |
371(c)(1),(2),(4) Date: |
February 14, 2014 |
PCT
Pub. No.: |
WO2013/027351 |
PCT
Pub. Date: |
February 28, 2013 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20140166380 A1 |
Jun 19, 2014 |
|
Foreign Application Priority Data
|
|
|
|
|
Aug 19, 2011 [JP] |
|
|
2011-179689 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01P
1/02 (20130101); E02F 9/0866 (20130101); F01P
5/06 (20130101); B60K 11/06 (20130101); F01P
2001/005 (20130101); B60Y 2200/412 (20130101) |
Current International
Class: |
F01P
1/02 (20060101); B60K 11/06 (20060101); F01P
5/06 (20060101); E02F 9/08 (20060101); F01P
1/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0649978 |
|
Apr 1995 |
|
EP |
|
1 628 000 |
|
Feb 2006 |
|
EP |
|
1 628 001 |
|
Feb 2006 |
|
EP |
|
2 358 165 |
|
Jul 2001 |
|
GB |
|
4-76930 |
|
Jul 1992 |
|
JP |
|
DE 4243593 |
|
Jul 1993 |
|
JP |
|
7 158111 |
|
Jun 1995 |
|
JP |
|
2548492 |
|
Sep 1997 |
|
JP |
|
2005 36447 |
|
Feb 2005 |
|
JP |
|
2005 145114 |
|
Jun 2005 |
|
JP |
|
Other References
Extended European Search Report issued Feb. 16, 2015 in Patent
Application No. 12825313.5. cited by applicant .
International Search Report Issued Oct. 23, 2012 in PCT/JP12/005013
Filed Aug. 7, 2012. cited by applicant.
|
Primary Examiner: Walters; John
Assistant Examiner: Johns; Hilary L
Attorney, Agent or Firm: Oblon, McClelland, Maier &
Neustadt, L.L.P.
Claims
The invention claimed is:
1. A construction machine comprising: an engine room; an engine
housed in the engine room; a heat exchanger provided at a first
side as one side in a longitudinal direction of the engine; an
axial-flow fan provided at the first side of the engine and adapted
to be rotated to generate, around the engine, a flow of cooling air
which enters the engine room from an outside of the engine room and
passes through the heat exchanger, the flow containing respective
direction components in a rotational direction, a centrifugal
direction, and an axial direction, of the fan; and an exhaust duct
having an air inlet opening and an air outlet opening and provided
in the engine room so as to extend in a fan axial direction
parallel with a rotation axis of the fan along the engine, the
exhaust duct adapted to guide the flow of the air so as to collect
the air, which flows at a downstream side of the fan in the fan
axial direction, in a region extending in the fan axial direction
and so as to discharge the air to an outside of the engine room,
wherein the exhaust duct has the air inlet opening at an upper part
thereof, the air inlet opening located at a position higher than a
bottom of the engine, and has the air outlet opening at a lower
part thereof at a position lower than the air inlet opening, the
exhaust duct being disposed in front of or behind a lower part of
the engine so as to suction the air flowing around the engine from
above and discharge the air from below by matching a swirling
direction of the flow of the air generated by the fan.
2. The construction machine according to claim 1, wherein the
exhaust duct is provided over substantially a whole region of the
engine in the fan axial direction, and the air inlet opening and
the air outlet opening are formed over substantially a whole length
of the exhaust duct in the fan axial direction.
3. The construction machine according to claim 1, wherein the
construction machine includes: a frame including a part which
configures a floor of the engine room; a partition member provided
to stand up in a posture of extension substantially in parallel
with a longitudinal direction of the engine on the frame to define
the engine room at a rear part of the frame; and a duct body in a
frame shape surrounding a space opened frontward, the duct body
being attached to a rear-side surface of the partition member to
form the exhaust duct in cooperation with the partition member.
4. The construction machine according to claim 1, further
comprising an air guide member for collecting air having passed in
the fan axial direction through a region in which the exhaust duct
collects the air, at a downstream side of the region, and for
guiding the air to the exhaust duct.
5. The construction machine according to claim 1, wherein the
exhaust duct has a shape being bent between the air inlet opening
and the air outlet opening.
6. The construction machine according to claim 5, wherein the
exhaust duct is bent along a direction in which air swirls around
the fan.
7. A construction machine comprising: an engine room; an engine
housed in the engine room; a heat exchanger provided at a first
side as one side in a longitudinal direction of the engine; an
axial flow fan provided at the first side of the engine and adapted
to be rotated to generate, around the engine, a flow of cooling air
which enters the engine room from an outside of the engine room and
passes through the heat exchanger, the flow containing respective
direction components in a rotational direction, a centrifugal
direction, and an axial direction, of the fan; an exhaust duct
having an air inlet opening and an air outlet opening and provided
in the engine room so as to extend in a fan axial direction
parallel with a rotation axis of the fan along the engine, the
exhaust duct adapted to guide the flow of the air so as to collect
the air, which flows at a downstream side of the fan in the fan
axial direction, in a region extending in the fan axial direction
and so as to discharge the air to an outside of the engine room; an
air guide member for collecting air having passed in the fan axial
direction through a region in which the exhaust duct collects the
air, at a downstream side of the region, and for guiding the air to
the exhaust duct, a hydraulic pump provided at a second side of the
engine opposite to the first side; and a pump cover for covering
the hydraulic pump to shield at least a part of the hydraulic pump
from the engine, the pump cover having an air inlet for taking in
air flowing around the engine and an air outlet for discharging the
taken-in air into the exhaust duct to function as the air guide
member.
8. The construction machine according to claim 7, wherein the pump
cover has a shape having an opening at a lower end and covering the
hydraulic pump at an upper side thereof to discharge air flowing in
through the opening to the exhaust duct.
Description
TECHNICAL FIELD
The present invention relates to a construction machine, such as an
excavator, the construction machine including a heat exchanger and
a device for cooling the heat exchanger.
BACKGROUND ART
A background art of the present invention will be described by
taking an excavator shown in FIG. 9 as an example.
The excavator includes a lower traveling body 1, an upper swirling
body 2 mounted pivotally thereon and having an upper frame 3 as a
base, various facilities and equipment including a cabin 4 mounted
on the upper frame 3, a working attachment (or a excavation
attachment) 5 attached to a front part of the upper frame 3, and a
counterweight 6 attached to a rear end part of the upper frame 3.
The cabin 4 is provided at a left-side front part in a traveling
direction of the upper frame 3. An engine room 8 which houses the
engine 7 is provided at a rear part of the upper frame 3.
FIG. 10 is a schematic cross-sectional view of arrangement of
equipment and a flow of air in the engine room 8, as viewed from a
rear side. The engine room 8 includes a long space in a left and
right direction surrounded by a bottom plate 9 that is a part of
the upper frame 3 and configures a floor of the engine room 8 and
an engine guard member 10 which is formed of a panel material. The
counterweight 6 is also a part of the engine guard member 10.
The engine 7 is installed in the engine room 8 in a posture
extending in a left and right direction. At one side (a right side
in the illustrated example) of right and left sides of the engine
7, a heat exchanger 11 including a radiator and an oil cooler for
cooling the engine 7 and a fan 12 of an axial flow type are
provided. An intake port 13 is provided on a right side portion of
an upper wall of the engine room 8, and an exhaust port 16 is
provided on a left side portion thereof. The fan 12 is rotated to
draw in outside-air through the intake port 13, causing the air to
pass through the heat exchanger 11, thereby cooling the heat
exchanger 11.
At the other side (the left side in the illustrated example) of the
left and right sides of the engine 7, a hydraulic pump 14 and a
pump cover 15 positioned over the hydraulic pump 14 are provided.
The pump cover 15 covers at least a part of the hydraulic pump 14
so as to prevent oil leaked and scattered in a mist shape from the
hydraulic pump 14 from falling on the engine 7, specifically, on an
exhaust system including a muffler not shown.
The rotation of the fan 12 forms a flow of air as indicated by
arrowheads in FIG. 10 on a downstream side of the fan 12. The flow
of air includes respective direction components in a rotational
direction and a centrifugal direction of the fan 12, and the air
moves from right to left in a long distance over substantially a
whole region on the downstream side of the fan 12, and reaches the
exhaust port 16 at a left end. The flow of air is therefore
susceptible to large resistance and likely to form turbulence. This
involves a decrease in exhaust efficiency.
As a technique for solving this problem, Patent Documents 1 and 2
disclose providing a groove, that is, a concave path, vertically
extending to a portion behind a fan in front of the counterweight 6
forming a rear surface of the engine room 8, and directly
collecting air blown out from the fan 12 to directions including a
swirling direction and a radial direction of the fan 12, through
the groove, and discharging the air outside the engine room;
however, this technique does not actually improve exhaust
efficiency of the air for the following reason. The air flowing as
described above actually moves while swirling a whole region of a
fan downstream side due to the component in a fan axial direction
as described above. On the other hand, according to the prior art
described in Patent Documents 1 and 2 above, only the air blown out
from the fan 12 to the radial direction and the swirling direction
is captured and discharged; air having passed through a majority of
a region at the fan downstream side, therefore, cannot be
collected. Furthermore, there is great airflow resistance in the
inlet portion of the groove, which degrades air volume
performance.
In the prior-art technique, it is possible to widen an air
capturing range in the fan axial direction by increasing a groove
width, in order to increase the air volume performance; however,
the expansion of the groove width must be significantly constrained
because the expansion thereof degrades the original function of the
counterweight.
Patent Document 1: Japanese Patent Application Publication No.
2005-36447
Patent Document 2: Japanese Patent Application Publication No.
2005-145114
SUMMARY OF THE INVENTION
An object of the present invention is to provide a construction
machine having an engine room, the control machine being capable of
efficiently collecting air flowing in the engine room and improving
exhaust efficiency. The construction machine includes: an engine
room; an engine housed in the engine room; a heat exchanger
provided at a first side as one side in a longitudinal direction of
the engine; a fan of an axial-flow type provided at the first side
of the engine and adapted to be rotated to generate, around the
engine, a flow of cooling air which enters the engine room from an
outside of the engine room and passes through the heat exchanger,
the flow containing respective direction components in a rotational
direction, a centrifugal direction, and an axial direction, of the
fan; and an exhaust duct having an air inlet opening and an air
outlet opening and provided in the engine room so as to extend in a
fan axial direction parallel with a rotation axis of the fan along
the engine, the exhaust duct adapted to guide the flow of the air
so as to collect the air, which flows at a downstream side of the
fan in the fan axial direction, in a region extending in the fan
axial direction and so as to discharge the air to an outside of the
engine room.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional plan view of a rear part of
an excavator according to a first embodiment of the present
invention.
FIG. 2 is a cross-sectional view of the rear part of the excavator
in FIG. 1 along a line II-II.
FIG. 3 is a cross-sectional view of the rear part of the excavator
in FIG. 1 along a line III-III.
FIG. 4 is a cross-sectional view of the rear part of the excavator
in FIG. 1 along a line IV-IV.
FIG. 5 is a perspective view of the rear part of the excavator
according to the first embodiment.
FIG. 6 is a perspective view of an exhaust duct and a pump cover
according to the first embodiment.
FIG. 7 is a schematic cross-sectional side view according to a
second embodiment of the present invention, corresponding to FIG.
3.
FIG. 8 is an outline perspective view of an exhaust duct according
to the second embodiment.
FIG. 9 is a side view of an example of an excavator to which the
present invention is applied.
FIG. 10 is a rear-surface cross-section view of a conventional
cooling device corresponding to FIG. 2.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention are described with reference
to FIGS. 1 to 8. These embodiments are applications of the present
invention to the excavator shown in FIG. 9. Thus, the excavator
according to the embodiments includes: the lower traveling body 1;
the upper swirling body 2 mounted thereon so as to be slewable and
including the upper frame 3 as a base; various facilities and
equipment including the cabin 4 mounted on the upper frame 3; the
working attachment (or the excavating attachment) 5 attached to the
front part of the upper frame 3, and the counterweight 6 attached
to the rear end part of the upper frame 3. The cabin 4 is provided
at the left-side front part in the traveling direction of the upper
frame 3. An engine room 8 for housing the engine 7 is provided at
the rear part of the upper frame 3. The engine room 8 includes a
long space in the right and left direction surrounded by a bottom
plate 9 configuring the floor and an engine guard member 10 formed
of a panel material. The counterweight 6 also forms a part of the
engine guard member 10.
The engine 7 is installed in the engine room 8 in a posture
extending in the left and right direction. At one side (the right
side in the illustrated example) of the left and right direction of
the engine 7, a heat exchanger 11 and a fan 12 of an axial flow
type are provided, the heat exchanger 11 including a radiator and
an oil cooler for cooling the engine 7. The engine room 8 is
provided with an intake port 13 on the right side portion of the
upper wall of the engine room 8. The fan 12 is adapted to be
rotated to draw in outside-air through the intake port 13 and cause
the air to pass through the heat exchanger 11, thereby cooling the
heat exchanger 11.
At the other side (the left side in the illustrated example) of the
right and left sides of the engine 7, provided are a hydraulic pump
14 and a pump cover 17 positioned over the hydraulic pump 14. The
pump cover 17 partitions between the engine 7 and the hydraulic
pump 14 to prevent oil leaked and scattered in a mist shape from
the hydraulic pump 14 from falling on the engine 7, specifically,
on an exhaust system including a muffler not shown.
The rotation of the fan 12 forms a flow of air as indicated by
arrowheads in FIGS. 1 to 4 and FIG. 7 at a downstream side of the
fan 12. The flow of air includes respective direction components in
a rotational direction, a centrifugal direction and an axial
component, of the fan 12.
Next are described details of a first embodiment of the present
invention with reference to FIGS. 1 to 6.
The excavator according to the first embodiment includes an exhaust
duct 18 in addition to the above configuration elements. The
exhaust duct 18 is provided at a front lower part of the engine 7
in the engine room 8, in a posture extending in a fan axial
direction (a right and left direction of the excavator) along the
engine 7. The exhaust duct 18 is composed of a duct body 19 and a
partition plate 20 which is located in front of the engine 7. The
partition plate 20 is one of partition members that partition a
space above the upper frame 3 into front and rear portions to
thereby define the engine room 8 at a rear part of the upper frame
3. The partition plate 20 is provided to stand up on the bottom
plate 9 at a position in front of the engine 7, extending in a
right and left direction over substantially a whole region in the
left and right direction of the bottom plate 9.
As shown in FIG. 5, the duct body 19 integrally has a front
sidewall 19a positioned in front of the partition plate 20 with a
distance from the partition plate 20, and left and right sidewalls
19b and 19c extending backward from both left and right ends of the
front sidewall 19a. The sidewalls 19a to 19c form a frame body long
in the right and left direction and surrounding an interior space
opened to a front side and both upper and lower sides. The duct
body 19 is attached to a rear surface of the partition plate 20 on
the bottom plate 9 to thereby form the exhaust duct 18 having an
air inlet opening 21 and an air outlet opening 22 each extending in
a right and left direction, at upper and lower ends,
respectively.
The bottom plate 9 is provided with an exhaust port 23 opened below
the engine room 8 at a position corresponding to the air outlet
opening 22 of the exhaust duct 18. The exhaust duct 18 is thus
allowed to draw in an air moving around the engine 7 into the
exhaust duct 18 through the air inlet opening 21 at an upper end of
the exhaust duct 18 and discharge the air through the air outlet
opening 22 at a lower end and the exhaust port 23 below the air
outlet opening 22. As shown in FIGS. 5 and 6, a notch 24 is formed
at a right upper end part of the front sidewall 19a of the duct
body 19, that is, at a portion located at a most upstream side of
the flow of air as a portion located in front of the fan 12. The
notch 24 facilitates introduction of the air flowing having
respective direction components in the rotational and centrifugal
directions of the fan 12, into the exhaust duct 18.
As shown in FIGS. 3 and 4, the exhaust duct 18 according to the
first embodiment has a shape of being bent at a vertically
intermediate position so as to direct a lower half part of the
exhaust duct 18 obliquely backward, that is, a shape substantially
along a swirling direction of the air around the fan 12.
The exhaust duct 18 may include a sound-absorption member, such as
glass wool, which is fixed to an inner surface of the sidewall
configuring the exhaust duct 18.
The exhaust duct 18 is preferably provided over substantially a
whole length of the engine 7 as shown in the drawings or a larger
range so as to be able to collect the air flowing around the engine
7 over a large possible range in the fan axial direction as long as
possible. The present invention, however, does not exclude an
embodiment where the exhaust duct 18 is shorter than the whole
length of the engine 7 for the reason of a relationship with a
layout of other devices and other reasons. The phrase of "the
exhaust duct collects air that flows at a downstream side of the
fan in the fan axial direction, in a region extending in the fan
axial direction" in the present invention refers to not only
collecting the air blown out from the fan 12 to the swirling
direction and the radial direction as described in the prior art,
but also collecting the air moving to a downstream side of the fan
12 in the fan axial direction, in a permissible maximum large range
including a region extending in the fan axial direction, preferably
the whole length of the engine 7 or a region near the whole
length.
On the other hand, the pump cover 17 has a shape that fulfills an
air guide function of guiding the air flowing around the engine 7,
to the exhaust duct 18 at a most downstream side of the air, in
addition to the original function, that is, the function of
covering at least a part of the hydraulic pump 14 (covering from
above in the example shown in FIGS. 1 and 2) to prevent a leakage
or splashing oil from the hydraulic pump 14 from reaching the
engine 7.
Specifically, the pump cover 17 integrally includes a body wall 17c
for covering the hydraulic pump 14 at a side of the engine 7 from
above, and a sidewall 17b extending downward from a peripheral edge
of the body wall 17c. The body wall 17c and the sidewall 17b cover
the hydraulic pump 14 thereabove, and configure an air guide member
surrounding a space opened below, that is, the air guide member
which forms a lower opening 26, as shown in FIG. 4. Moreover, the
air guide member configured by the body wall 17c and the sidewall
17b has a guide part 25 extended in the fan axial direction toward
the air inlet opening 21 of the exhaust duct 18, at a front end
part of the air guide member, that is, at a portion positioned in
front of the engine 7. The air guide member configured by the pump
cover 17, therefore, has a shape capable of allowing the air
swirling around the engine 7 to be blown through a rear part of the
lower opening 26 as an air inlet and to be discharged through an
air outlet as an opening at an end part of the guide part 25 to the
air inlet opening 21 of the exhaust duct 18.
The guide part 25 may be arranged to cover a left side end part of
the air inlet opening 21 from above as shown in FIG. 2, or may be
arranged to be positioned at a slightly left side of the left side
end part of the air inlet opening 21. Although the pump cover 17
shown in FIGS. 1 to 6 has an upper sidewall 17a extending upward
from an outer side edge part of the body wall 17c of the pump cover
17, the upper sidewall 17a can be suitably omitted.
The excavator according to the present embodiment, including the
exhaust duct 18, can have an improved exhaust efficiency.
Specifically, the exhaust duct 18 is capable of collecting the air
moving in the fan axial direction while swirling by the rotation of
the fan 12 over a specific region (a region over the whole length
of the engine in the present embodiment) extending in a moving
direction of the air and discharging it. Furthermore, the air inlet
opening 21 of the exhaust duct 18, provided over substantially the
whole length of the exhaust duct 18, makes airflow resistance in
the air inlet portion be small. This allows the exhaust efficiency
be significantly improved, compared to the exhaust duct which can
collect only the air blown out in the swirling direction and the
radial direction from the fan 12 as described in the prior art.
Furthermore, according to the present embodiment, the following
effects can be obtained.
(i) The exhaust duct 18, disposed in front of the lower part of the
engine 7 so as to draw in the air flowing around the engine 7 from
above and discharge the air from below, can smoothly draw in and
discharge the air with small airflow resistance. This allows
exhaust efficiency to be further improved.
(ii) The exhaust duct 18, adapted to discharge the collected air
downward of the exhaust duct 18, can suppress influence of machine
noise leaked out from the inside of the engine room 8 to an
outside, for example, noise generated by the engine 7 and the
hydraulic pump 14, to the surrounding.
(iii) The exhaust duct 18, configured by utilization of the
partition plate 20 which is a part of the engine guard, can have a
small number of parts and can be assembled by a small number of
steps, thus involving low cost.
(iv) The pump cover 17, functioning as an air guide member for
guiding air having passed through a fan-axial region of the
provided exhaust duct 18 to the exhaust duct 18 at a downstream
side of the exhaust duct 18, contributes to an improved exhaust
efficiency in cooperation with suppressing generation of a
turbulent flow due to leakage air. Furthermore, combined use of the
pump cover 17 for the air guide member allows the air guide member
to be installed, without difficulty, in the engine room 8, limited
space, in addition to avoidance of increase in the number of
parts.
(v) The exhaust duct 18, having a shape of being bent to a front
and rear direction when viewed at a side wherein a vertical
intermediate part of the exhaust duct 18 swells to the front beyond
the upper and lower ends, that is, a shape of being along a
direction in which air swirls around the fan 12, makes it possible:
to enhance reflection and attenuation effects of sound in the
exhaust duct 18; to enhance a noise reduction effect by suppressing
"direct sound" that is directly leaked out through the exhaust duct
18; and to enhance exhaust efficiency by bettering the flow of air
in the exhaust duct 18.
A second embodiment of the present invention will be described with
reference to FIGS. 7 and 8. The second embodiment, while being
based on the excavator according to the first embodiment, includes
an exhaust duct 27 in place of the exhaust duct 18. Differently
from the exhaust duct 18, the exhaust duct 27 is configured as an
independent housing that encloses an interior space, which is long
in right and left direction, by only the exhaust duct 27 itself,
while, similar to the exhaust duct 18, the exhaust duct 27 is
installed in a posture extending in a right and left direction in
front of the engine 7 in the engine room 8. The exhaust duct 27 has
a shape that is bent in a front and rear direction at vertically
arranged two positions so that upper and lower part of the exhaust
duct 27 direct obliquely backward, that is, so that a vertically
intermediate part thereof swells to the front as compared with the
upper and lower ends. Thus, the exhaust duct 27 has a shape of more
fitting the swirling direction of air around the fan 12. The
exhaust duct 27 also has an air inlet opening 28 and an air outlet
opening 29, and the air outlet opening 29 is provided at a lower
end of the exhaust duct 27 similarly to the air outlet opening 22
in the first embodiment, while the air inlet opening 28 is opened
backward at an upper part of the exhaust duct 27. Besides, the
exhaust duct 27 has a larger height than that of the exhaust duct
18 in the first embodiment, and the air inlet opening 28 is
adjacent to an upper part of the engine 7.
The exhaust duct 27 further has the following effects, in addition
to the effects of the exhaust duct 18 according to the first
embodiment. First, the exhaust duct 27, which surrounds the
interior space by itself, has a high degree of freedom in an
arrangement position thereof, being allowed to be disposed at an
optimum position in accordance with a size of the engine room 8 and
a device layout. Second, the exhaust duct 18, adapted to receive
the flow of air around the engine 7 at a higher position than a
position of the exhaust duct 18 according to the first embodiment,
can collect the air more smoothly and without leakage. Third, the
exhaust duct 18, having a shape of being bent at vertically
arranged two positions (or may be at more positions), can more
effectively suppress leakage of machine noise to an outside.
The present invention is not limited to the first and second
embodiments. The present invention also includes the following
modes, for example.
(1) An exhaust duct may be arranged behind the engine, when there
is no limitation of a space or device layout in the engine
room.
(2) In the present invention, an exclusive air guide member
configured separately from the pump cover may be arranged at a
downstream side of the engine in the fan axial direction.
(3) The present invention can be applied not only to the excavator,
but can be also widely applied to a crusher, a demolition machine,
and the like configured by use of a matrix of the excavator, for
example.
An object of the present invention is to provide a construction
machine having an engine room, the control machine being capable of
efficiently collecting air flowing in the engine room and improving
exhaust efficiency. The construction machine includes: an engine
room; an engine housed in the engine room; a heat exchanger
provided at a first side as one side in a longitudinal direction of
the engine; a fan of an axial-flow type provided at the first side
of the engine and adapted to be rotated to generate, around the
engine, a flow of cooling air which enters the engine room from an
outside of the engine room and passes through the heat exchanger,
the flow containing respective direction components in a rotational
direction, a centrifugal direction, and an axial direction, of the
fan; and an exhaust duct having an air inlet opening and an air
outlet opening and provided in the engine room so as to extend in a
fan axial direction parallel with a rotation axis of the fan along
the engine, the exhaust duct adapted to guide the flow of the air
so as to collect the air, which flows at a downstream side of the
fan in the fan axial direction, in a region extending in the fan
axial direction and so as to discharge the air to an outside of the
engine room.
According to the construction machine, air that moves to the fan
axial direction while swirling by the rotation of the fan is
collected in a region whose range in the fan axial direction which
is a movement direction of the air is limited. Besides, no
requirement for a groove for the collection differently from the
prior art allows airflow resistance at the inlet portion of the air
allows not to be large. These enable exhaust efficiency to be
substantially improved as compared with the prior art that enables
only collection of air blown out in the swirling direction and the
radial direction from the fan.
Preferably, the exhaust duct is provided over substantially a whole
region of the engine in the fan axial direction, and the air inlet
opening and the air outlet opening are formed over substantially a
whole length of the exhaust duct in the fan axial direction. This
exhaust duct can collect and discharge an airflow which moves to
the fan axial direction while swirling around the engine at a
downstream side of the fan, having particularly good exhaust
efficiency.
The exhaust duct preferably has the air inlet opening at an upper
part thereof and has the air outlet opening at a lower part
thereof, being disposed in front of or behind a lower part of the
engine so as to suction the air flowing around the engine from
above and discharge the air from below. The exhaust duct enables
the air around the engine to be drawn in, from above the exhaust
duct, by matching a swirling direction of the air, and discharged
from below, thereby allowing the air to be smoothly drawn in and
discharged with small airflow resistance to thereby allow exhaust
efficiency to be further improved. Besides, the exhaust duct,
adapted to discharge the air from a lower part of the exhaust duct,
can suppress influence of machine noise leaked out from the inside
of the engine room to an outside, for example, noise generated by
the engine and the hydraulic pump, to the surrounding.
Further, according the present invention, in the case of the
construction machine comprising a frame including a part which
configures a floor of the engine room and a partition member which
stands up in a posture of extending substantially in parallel with
a longitudinal direction of the engine on the frame to define the
engine room at a rear part of the frame, it is preferable that the
construction machine further comprises a duct body in a frame shape
surrounding a space opened to the front, the duct body being
attached to a rear-side surface of the partition member to form the
exhaust duct in cooperation with the partition member. The
combination of the partition member and the duct body allows the
exhaust duct to be formed at low cost by a small number of parts
and a small number of assembly processes by utilization of the
partition member which is a part of the engine guard constituting
the engine room.
Besides, the construction machine according to the present
invention, preferably, further includes an air guide member adapted
to collect air having passed in the fan axial direction a region in
which the exhaust duct collects the air, at a downstream side of
the region, and guide the air to the exhaust duct. The air guide
member, collecting the air temporarily passing through a collection
region of the exhaust duct at a downstream side of the collection
region and guiding the collected air to the exhaust duct, can
contribute to improved exhaust efficiency in cooperation with
suppressing generation of a turbulent flow due to leakage air.
In the case of the construction machine which includes a hydraulic
pump provided at a second side of the engine opposite to the first
side and a pump cover covering the hydraulic pump to shield at
least a part of the hydraulic pump from the engine, it is
preferable that the pump cover has an air inlet for taking in air
flowing around the engine and an air exit for discharging the
taken-in air into the exhaust duct to function as the air guide
member. This combined use of the pump cover for the air guide
member allows the air guide member to be installed without
difficulty in the engine room whose space is limited while
suppressing increase in the number of parts.
More specifically, the pump cover preferably has a shape having an
opening at a lower end and covering the hydraulic pump at an upper
side thereof to discharge air having flowed in through the opening
to the exhaust duct.
The exhaust duct preferably has a shape that is bent between the
air inlet opening and the air outlet opening. The bending of the
exhaust duct makes it possible to enhance reflection and
attenuation effects of sound in the exhaust duct and enhance a
noise reduction effect by suppressing "direct sound" that is
directly leaked out through the exhaust duct.
In this case, it is preferable that the exhaust duct is bent along
a direction in which air swirls around the fan. This shape of the
exhaust duct makes the flow of air in the duct smooth to thereby
enable exhaust efficiency to be further enhanced.
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